#include "SystemHead.h"
int main(int argc ,char* argv[])
{
    // printf("USER=%s\n",getenv("USER"));
    // printf("PASSWD=%s\n",getenv("PASSWD"));
    int c;
    fcntl(STDIN_FILENO,F_SETFL,O_NONBLOCK);
    while(1)
    {

        scanf("%d",&c);
        printf("read c: %d\n",c);
        sleep(1);
    }
    return 0;
}